Why is this medication prescribed?   

Isosorbide is used to prevent or treat chest pain (angina). It works by relaxing the blood vessels to the heart, so the blood and oxygen supply to the heart is increased.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?  

Isosorbide comes as a regular, sublingual, chewable, and extended-release (long-acting) tablet and extended-release (long-acting) capsule to be taken by mouth. The tablet usually is taken every 6 hours. The extended-release tablet usually is taken one or two times a day. The extended-release capsule usually is taken every 8-12 hours. Do not crush, chew, or divide the extended-release tablets or capsules. The sublingual or chewable tablet is used as needed to relieve chest pain that has already started or to prevent pain before activities known to provoke attacks (e.g., climbing stairs, sexual activity, heavy exercise, or being outside in cold weather). The chewable tablet also may be used every 2-3 hours to prevent chest pain. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take isosorbide exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Isosorbide controls chest pain but does not cure it. Continue to take isosorbide even if you feel well. Do not stop taking isosorbide without talking to your doctor. Stopping the drug abruptly may cause chest pain.

Isosorbide can lose its effectiveness when used for a long time. This effect is called tolerance. If your angina attacks happen more often, last longer, or are more severe, call your doctor.

If you are using isosorbide sublingual or chewable tablets for acute chest pain, you should carry the tablets with you at all times. If you are taking isosorbide and your chest pain is not relieved within 5-10 minutes, take another dose. Call for emergency assistance or go to a hospital emergency department if pain persists after you have taken three tablets (at 5-10-minute intervals) and 15-30 minutes have passed.

When an attack occurs, sit down. If you use chewable tablets, chew a tablet thoroughly and swallow it. To use the sublingual tablets, place a tablet under your tongue or between your cheek and gum and allow it to dissolve. Do not swallow the tablet. Try not to swallow saliva too often until the tablet dissolves.

Other uses for this medicine     

Isosorbide tablets are also used with other drugs to treat congestive heart failure. Talk to your doctor about the possible risks of using this drug for your condition.

What storage conditions are needed for this medicine?     

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Keep sublingual and chewable tablets in the original container. Do not open a container of sublingual or chewable isosorbide until you need a dose. Do not use tablets that are more than 12 months old. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose     

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know?     

Keep all appointments with your doctor and the laboratory.

Isosorbide regular and extended-release tablets or capsules should not be used for acute angina attacks. Continue to use isosorbide sublingual or chewable tablets to relieve chest pain that has already started.

If headache continues, ask your doctor if you may take acetaminophen. Your isosorbide dose may need to be adjusted. Do not take aspirin or any other medication for headache while using isosorbide unless you doctor tells you to.

The tablets may cause a sweet, tingling sensation when placed under your tongue. This sensation is not an accurate indicator of drug strength; the absence of a tingling sensation does not mean that the drug is not working.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Brand names     

Other names